1. Field of the Invention
This invention relates to a flash photographing system having a TTL automatic focusing device and more particularly to a system of the kind arranged to make pre-flashing and to control a main flashing light quantity on the basis of information resulting from the pre-flashing.
2. Description of the Related Art
There has been known a camera system arranged to make pre-flashing; to detect, through the lens of the camera (TTL), a reflection light reflected by an object to be photographed as a result of pre-flashing by means of a photosensitive element disposed within the camera; and to determine a main flashing light quantity according to the result of the detection. If such a flashing quantity controlling type camera system is equipped with an AF device, the camera must be provided with a light receiving sensor for an AF operation as well as a light receiving sensor for flash light quantity control. Both of these light receiving parts then must be arranged to measure mainly a light flux incident on the middle part of a view finder. This arrangement causes a considerable portion of a light flux coming through the lens of the camera to be guided to these light receiving parts. As a result, the view finder becomes dark.
This problem also has likewise affected a case where an AF system is provided on the so-called TTL type flash light quantity controlling camera which is arranged to control flashing light quantity by receiving a light reflected from a film surface as a result of flashing.